DE112012004529B4 - Device for monitoring a wind turbine blade and method therefor - Google Patents

Abstract

A method of monitoring a wind turbine blade, comprising the steps of: converting a load on the wind turbine blade of a wind turbine, including at least the wind turbine blade, to a moment; generating a reference value based on design information of the wind turbine blade and statistical information on the moment; andcomparing the torque with the reference value and determining a state of the wind turbine blade to enable efficient management and maintenance of the wind turbine blade, wherein generating the reference value comprises: calculating a first reference value based on design information of the wind turbine blade; calculating a second reference value based on statistical information of the Moments; andcombining the first reference value and the second reference value to produce the reference value; and wherein calculating the second reference value comprises: comparing a power of the wind turbine with its nominal power, the load being data measured on a pressure side or a suction side of the wind turbine blade.

Description

Technical field

The present invention relates to an apparatus and method for monitoring a wind turbine blade, and more particularly, to an apparatus and method for monitoring a wind turbine blade capable of generating a reference value, which is a reference of the blade condition determination, in accordance with blade design information and statistical information of the moment, and the like Ensure reliability of sheet condition determination.

Technology Background

In general, a wind power generation system is a system for rotating a blade using aerodynamic properties of the kinetic energy contained in an air stream to convert it to mechanical energy and rotating a generator using the mechanical energy to obtain electrical energy.

Such a wind power generation system is classified as a horizontal type and a vertical type according to a direction of a rotating shaft with respect to the ground, and is a gear configured to increase a rotation speed by a rotor having a blade and a hub to drive a generator, the generator configured to generate electricity, a cooling / heating system configured to appropriately set an operating temperature of each of the components, and a power converter system configured to control power, educated.

Thereby, if the sheet is defective, a downtime is increased, and replacement costs are also largely consumed. In particular, blade contamination due to salt, dust, or the like often occurs in an offshore wind power generation system. Accordingly, a condition of the sheet should be monitored in real time.

Accordingly, even though a sensor is installed on the blade to be used in monitoring the blade, since steady-state and non-steady-state conditions are repeated immediately in wind power generation unlike other power generation, effective and accurate monitoring cannot be performed become.

In addition, in the case of offshore wind power generation, since access to the blade is limited due to fluctuations in weather or climate, effective management and maintenance of the blade cannot be performed, and hence prompt treatment in the event of damage to the blade can not be carried out.

The US 2009/0 246 019 A1 shows for example a method for monitoring a wind turbine with fiber optic sensors.

To solve the problems, an object of the present invention is to provide an apparatus and method for monitoring a wind turbine blade with the ability to ensure the reliability of blade condition determination and to perform effective blade management and maintenance.

This task is solved with the means of the independent claims. Preferred developments are the subject of the dependent claims.

A method of monitoring a wind turbine blade in accordance with an aspect of the present invention includes converting the load on a blade to a moment; generating a reference value based on design information of the sheet and statistical information on the moment; and comparing the torque with the reference value and determining a state of the sheet.

In the present invention, the moment can be converted based on physical properties of a material and shape characteristics of the sheet.

In the present invention, generating the reference value includes calculating a first reference value based on design information of the sheet; computing a second reference value based on statistical information of the moment; and combining the first reference value and the second reference value to generate the reference value.

In the present invention, the first reference value can be calculated by reflecting a model parameter in a design load of the sheet.

In the present invention, calculating the second reference value may include calculating a length of a normal section based on an average and a standard deviation of the torque; and calculating the second reference value based on the mean value of the moment and the length of the normal section.

In calculating the length of the normal portion of the present invention, the mean and standard deviation of the moment can be obtained by reflecting an average and a standard deviation of the current time in an average and a standard deviation, which were calculated cumulatively to the earlier time.

In the present invention, calculating the second reference value includes comparing a wind turbine power to a rated power when the load is data measured on a pressure side or a suction side of the blade; and reflecting a fluctuation in the performance of the wind turbine or a fluctuation in the pitch angle of the blade in the statistical information of the moment according to the comparison result.

In the present invention, the fluctuation in the performance of the wind turbine can be reflected in the statistical information of the moment when the performance of the wind turbine is the rated power or less, and the fluctuation in the pitch angle of the blade can be reflected in the statistical information of the moment when the power of the wind turbine is greater than the nominal power.

In the present invention, the reference value may include a caution reference value for determining a caution state of the sheet, a warning reference value for determining a warning condition, and an emergency reference value for determining an emergency condition.

In the present invention, the method may further include alerting the condition of the sheet when the condition of the sheet corresponds to any one of the caution, warning, and emergency conditions.

A wind turbine blade monitoring device according to another aspect of the present invention includes a torque conversion unit configured to convert the load on the wind turbine blade to a torque; a state determination unit configured to compare the torque with a reference value and determine a state of the sheet; and a reference value generation unit configured to generate the reference value based on design information of the sheet and statistical information on the moment.

In the present invention, the torque conversion unit can convert the load to the torque based on physical properties of a material and shape characteristics of the sheet.

In the present invention, the reference value generation unit combines a first reference value calculated based on design information of the sheet and a second reference value calculated based on statistical information of the moment to generate the reference value.

In the present invention, the reference value generation unit may reflect a model parameter in a design load of the sheet and calculate the first reference value.

In the present invention, the reference value generation unit can calculate a length of a normal section based on an average and a standard deviation of the torque and calculate the second reference value based on the average of the moment and the length of the normal section.

In the present invention, the reference value generating unit may reflect a fluctuation in the performance of the wind turbine or a fluctuation in the pitch angle of the blade in the statistical information of the moment when the load is data measured on a pressure side or suction side of the blade.

In the present invention, when the wind turbine power is a nominal power or less, the fluctuation in the wind turbine power can be reflected in the mean and the standard deviation of the torque, and the fluctuation in the pitch angle can be reflected in the mean and the standard deviation of the torque be reflected if the power of the wind turbine is greater than the nominal power.

In the present invention, the reference value may include a caution reference value for determining a caution state of the sheet, a warning reference value for determining a warning condition, and an emergency reference value for determining an emergency condition.

In the present invention, the state determination unit can determine that the state of the sheet is the caution state when the moment deviates from the caution reference value, determine that the state of the sheet is the warning state when the moment deviates from the warning reference value, and determine that the State of the sheet is the emergency state when the moment deviates from the emergency reference value.

In the present invention, the apparatus may further include an alarm unit configured to warn of the condition of the sheet when the condition of the sheet corresponds to any of the caution, warning, and emergency conditions.

Advantageous effects of the invention

According to the present invention, since the reference value serving as a reference of the sheet condition determination is generated according to the sheet design information and the statistical information of the moment, the reliability of the sheet condition determination can be ensured in a steady state and a non-steady state.

In addition, according to the present invention, since learning of the statistical information of the moment is performed, a reference value can be generated with higher reliability because the statistical information of the moment is accumulated, and thus the reliability of the sheet condition determination can be improved.

As described above, according to the present invention, since the reliability of sheet condition determination can be improved, efficient management and maintenance of the sheet becomes possible.

Figure list

• 1 11 is a view for explaining a position at which the load on a blade is measured on a wind turbine blade monitoring apparatus according to an embodiment of the present invention;
• 2nd 12 is a block diagram showing a configuration of the wind turbine blade monitoring device according to an embodiment of the present invention;
• 3rd FIG. 10 is a flowchart showing a reference value generation process of a method for monitoring a wind turbine blade according to an embodiment of the present invention;
• 4th FIG. 12 is a view exemplarily showing a reference value and torque measurement data by 3rd were generated;
• 5 FIG. 12 is a flowchart showing a reference value generation process of the wind turbine blade monitoring method according to another embodiment of the present invention;
• 6 and 7 are views to exemplarily show a reference value and torque measurement data by 5 were generated; and
• 8th FIG. 12 is a flowchart showing a blade state determination process of the wind turbine blade monitoring method according to the embodiment of the present invention.

Description of embodiments

Hereinafter, an apparatus and a method for monitoring a wind turbine blade according to the present invention will be described in detail with reference to the accompanying drawings. In this process, thicknesses of lines, sizes of components or the like shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described below are defined taking into account functions in the present invention, and can be changed according to the intention or custom of a user or an operator. Accordingly, definitions of terms based on all content are provided throughout the description.

1 10 is a view for explaining a position at which the load on a blade is measured on a wind turbine blade monitoring apparatus according to an embodiment of the present invention.

As in 1 Generally, points where a stress measurement is made on the sheet are shown in a printed page 110 , a suction side 120 , a leading edge 130 and a trailing edge 140 classified.

Here the print page means 110 a front surface of the blade configured to receive wind and the suction side 120 means a rear surface of the blade that does not absorb wind. The leading edge 130 and the trailing edge 140 correspond to corner points of the printed page 110 and the suction side 120 and take up torque.

2nd 10 is a block diagram showing a configuration of the wind turbine blade monitoring device according to the embodiment of the present invention.

As in 2nd shown, the device for monitoring the wind turbine blade according to the embodiment of the present invention comprises a light guide sensor unit 10th , an optical wavelength measuring unit 20th , a data diagnosis processing unit 30th , a moment conversion unit 40 , an operational information input unit 50 , a reference value generation unit 60 , a state determination unit 70 , a storage unit 80 and an alarm unit 90 .

The light guide sensor unit 10th includes a plurality of wavelength division multiplexing (WDM) light guide sensors, and each light guide sensor reflects a laser emitted from a light source (not shown) at a specific wavelength and transmits the laser to the optical wavelength measurement unit 20th .

Referring to 1 can the majority of light guide sensors on the pressure side 110 , the suction side 120 , the leading edge 130 and the trailing edge 140 of the blade must be installed at 90 ° intervals.

The optical wavelength measurement unit 20th measures one of the light guide sensor unit 10th reflected wavelength to generate a plurality of measurement data and transmits the data to the data diagnosis processing unit 30th .

Here the optical wavelength measuring unit 20th Generate measurement data every measurement period, and the measurement period can be according to the designer's intention and the specification of the light guide sensor and the optical wavelength measurement unit 20th can be selected differently. For example, the optical wavelength measuring unit 20th Generate measurement data every 0.01 s (ie, 100 Hz) to send the data to the data diagnostic processing unit 30th transferred to.

The data diagnostic processing unit 30th diagnoses whether there is error data in the majority of the measurement data from the optical wavelength measurement unit 20th were entered, and converts the diagnosed measurement data into a load, which is physical data, the load to the torque conversion unit 40 transferred to.

The moment conversion unit 40 converts that from the data diagnosis processing unit 30th input load into an equivalent torque to the torque to the condition determination unit 70 transferred to.

In this case, the torque conversion unit 40 physical properties (E) of a material and shape characteristics (Izz, y) of the sheet reflect in the load (ε) and convert them into a moment (M) according to Eq. 1 um. $$M=-\frac{\epsilon \cdot E{\mathrm{I.}}_{\mathrm{e.g.}\mathrm{e.g.}}}{y}$$

) dar, wobei es sich um geometrische Information handelt.Here M represents the moment, ε represents the load, E represents the physical properties of a material, Izz represents the moment of inertia and y represents a root of a radius of rotation r (ie, $\sqrt{r}$

), which is geometrical information.

Since the interpretation of the load of the wind turbine is carried out in units of the moment, the measured load is converted into a moment in order to be used for the blade condition determination.

That through the moment conversion unit 40 converted moment is in the storage unit 80 stored to be used to generate statistical information of the next moment, which is described in detail below.

The operational information input unit 50 receives the operating information of the wind turbine to the operating information to the reference value generating unit 60 transferred to. Here, the operating information includes information about the power (energy) of the wind turbine and an angle of incidence of the blade.

The reference value generation unit 60 generates a reference value based on the design information of the sheet and the statistical information of the torque conversion unit 40 converted torque and supplies the reference value to the state determination unit 70 .

The reference value generation unit can be found here 60 calculate a first reference value based on the design information of the sheet and a second reference value based on the statistical information of the moment and then combine the first reference value and the second reference value according to a weighting to produce a final reference value.

The design information of the sheet may include the design load of the sheet, which is determined in units of the moment, and the design load may include a maximum design load and a minimum design load.

The statistical information of the moment may include a mean and a standard deviation of the moment, and the mean and the standard deviation of the moment may consist of a plurality of moment values that are sequential in the storage unit 80 are stored by the torque conversion unit 40 be calculated.

In addition, the reference value means a value that is a reference of the sheet condition determination, and it may be formed by a plurality of reference values according to a method for defining a condition of the sheet.

For example, when the states of the sheet are defined as a steady state, a caution state, a warning state, and an emergency state according to an error level, the reference value can be formed by a caution reference value for determining whether the state is the caution state, a warning reference value for determining whether the State is the warning state, and an emergency reference value for determining whether the state is the emergency state.

Meanwhile, when generating the second reference value based on the statistical information of the moment, the reference value generating unit 60 generate a reference value in different methods according to a position in which the load on the sheet is measured.

In particular, if the positions at which the load is measured, the pressure side 110 and the suction side 120 of the sheet are the reference value generating unit 60 the power of the wind turbine and the pitch angle of the blade by the operational information input unit 50 were entered, reflecting the statistical information of the moment to calculate the second reference value.

Because the print page 110 and the suction side 120 of the sheet by a pushing force different from the leading edge 130 and the trailing edge 140 of the sheet are affected, face the printed page 110 and the suction side 120 Features depend on the performance of the wind turbine and the setting angle of the blade.

As described above, a specific process for generating a reference value using the reference value generation unit 60 in detail with reference to 3rd to 7 described.

The state determination unit 70 compares the moment from the moment conversion unit 40 was entered with the reference value from the reference value generating unit 60 was provided to determine the condition of the sheet.

For example, if the reference value includes the caution reference value, the warning reference value, and the emergency reference value, the state determination unit can 70 compare the moment with the caution reference value, the warning reference value, and the emergency reference value to determine which state of the steady state, the caution state, the warning state, and the emergency state is the state of the sheet.

If it is determined that the sheet corresponds to any one of the caution state, the warning state and the emergency state, the state determination unit can 70 the alarm unit 90 control to execute an appropriate warning message.

As described above, the specific process of determining the state of the sheet and controlling the alarm unit 90 using the state determination unit 70 below with reference to 8th described.

The through the moment conversion unit 40 converted moments are sequentially stored in the storage unit 80 saved according to a measurement time.

The alarm unit 90 gives information of the state of the sheet according to the control of the state determination unit 70 out. For example, the alarm unit 90 Output information of the steady state, the precautionary state, the warning state and the emergency state of the sheet.

The alarm unit 90 may display and output the state of the sheet by a warning lamp (not shown) or a display board (not shown), or output the state of the sheet using sound through a speaker (not shown) or the like.

3rd 10 is a flowchart showing a reference generation process of a method for monitoring a wind turbine blade according to an embodiment of the present invention, and 4th FIG. 12 is a view exemplarily showing a reference value and torque measurement data by 3rd were generated.

3rd FIG. 12 shows a process of generating a reference value using the reference value generation unit 60 when a load measurement position the leading edge 130 and the trailing edge 140 of the sheet is.

As in 3rd shown, the reference value generation unit calculates 60 first a first reference value based on the design information of the sheet ( S100 ).

In particular, the reference value generation unit 60 reflect a model parameter in a maximum design load and a minimum design load of the sheet to calculate a first reference value.

$$W_{l-max}=v_3\cdot M_{D-max},{\text{ W}}_{I-min}=v_4\cdot M_{D-min}$$

$$E_{l-max}=v_5\cdot M_{D-max},{\text{ E}}_{I-min}=v_6\cdot M_{D-min}$$

For example, if the first reference value includes a first caution reference value, a first warning reference value, and a first emergency reference value, the first caution reference value (C _1-max , C _1-min ), the first warning reference value (W _1-max , W _1-min ) and the first emergency reference value (E _1-max , E _1-min ) according to the following Eq. 2 to Eq. 4 can be calculated. $${\mathrm{C.}}_{l-max}={\mathrm{<figure-callout\; id="1"\; label="v"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">v</figure-callout>}}_1\cdot M_{D-max},{\mathrm{C.}}_{\mathrm{I.}-min}=v_{\mathrm{2nd}}\cdot M_{D-min}$$

$$W_{l-max}=v_{\mathrm{3rd}}\cdot M_{D-max},{\text{W}}_{\mathrm{I.}-min}=v_{\mathrm{4th}}\cdot M_{D-min}$$

$$E_{l-max}=v_5\cdot M_{D-max},{\text{E}}_{\mathrm{I.}-min}=v_6\cdot M_{D-min}$$

Here, M _D-max and M _{D-min represent} a maximum design load or a minimum design load of the sheet, and v ₁ to v ₆ represent model parameters. The model parameters are parameters that are multiplied by the maximum design load and the minimum design load, which can be selected as a value corresponding to 1σ, 2σ and 3σ on the standard normal distribution of the design load.

For example, v ₁ and v _{2 can} be selected as 0.68, which corresponds to 1σ, v ₃ and v ₄ can be selected as 0.95, which corresponds to 2σ, and v ₅ and v ₆ can be selected as 0.99, which corresponds to 3σ. However, these values are only exemplary and the model parameters can be selected as different values according to the designer's intention or the specification of a sheet used.

Meanwhile, the reference value generation unit calculates 60 a second reference value based on statistical information of the moment ( S110 ).

In particular, the reference value generation unit 60 calculate a length (normal distance; L) of a normal section based on an average value and a standard deviation of the torque and the second reference value based on the average value of the moment and the length L of the normal section.

$$W_{2-max}=M_{avg}+s_3\cdot L{\text{, W}}_{2-min}=M_{avg}-s_4\cdot L$$

$$E_{2-max}=M_{avg}+s_5\cdot L{\text{, E}}_{2-min}=M_{avg}-s_6\cdot L$$

For example, if the second reference value includes a second caution reference value, a second warning reference value, and a second emergency reference value, the second caution reference value (C _2-max , C _2-min ), the second warning reference value (W _2-max , W _2-min ) and the second emergency reference value (E _2-max , E _2-min ) according to the following Eq. 5 to Eq. 7 can be calculated. $${\mathrm{C.}}_{\mathrm{2nd}-max}=M_{avG}+s_1\cdot L\text{,}{\mathrm{C.}}_{\mathrm{2nd}-min}=M_{avG}-s_{\mathrm{2nd}}\cdot L$$

$$W_{\mathrm{2nd}-max}=M_{avG}+s_{\mathrm{3rd}}\cdot L{\text{, W}}_{\mathrm{2nd}-min}=M_{avG}-s_{\mathrm{4th}}\cdot L$$

$$E_{\mathrm{2nd}-max}=M_{avG}+s_5\cdot L{\text{, E}}_{\mathrm{2nd}-min}=M_{avG}-s_6\cdot L$$

Here M _{avg represents} an average of the moment, L represents a length of the normal section and s ₁ to s ₆ represent statistical parameters.

The statistical parameters are parameters that are multiplied by the length of the normal section, similar to the model parameter mentioned above, which can be selected as a value corresponding to 1σ, 2σ and 3σ on the standard normal distribution of the moment. However, these values are only exemplary and the statistical parameters can be selected as different values according to the designer's intention or a specification of the sheet used.

Meanwhile, the length L of the normal section is a value to substantially determine the second reference value, which is calculated based on the mean value and the standard deviation of the torque.

The reference value generation unit 60 can add the mean and the standard deviation of the torque, which are multiplied by the proportional constants k ₁ and k, by the length L of the normal section according to the following Eq. 8 to calculate. $$L={\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">k</figure-callout>}}_1\cdot M_{avG}+k_{\mathrm{2nd}}\cdot {\sigma }_M$$

Here M _avg and σ _{M represent} the mean or standard deviation of the moment and k ₁ and k ₂ represent proportional constants. The proportional constants k ₁ and k ₂ can be selected differently according to the designer's intention. For example, k ₁ and k ₂ can be selected as 0.1 and 0.9, respectively.

Meanwhile, the reference value generation unit 60 add the mean and the standard deviation, which were calculated cumulatively at the current time and multiplied by the proportional constants k ₁ and k ₂ , by the length L of the normal section according to the following Eq. 9 to calculate. $$L={\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">k</figure-callout>}}_1\cdot M_{avG}\left(t\right)+k_{\mathrm{2nd}}\cdot {\sigma }_{avG}\left(t\right)$$

Here, M _avg (t) and σ _avg (t) represent the cumulatively calculated mean and the cumulatively calculated standard deviation of the moment, and k ₁ and k ₂ represent the proportional constants.

$${\sigma }_{avg}\left(t\right)=\frac{\left(t-1\right)\cdot {\sigma }_{avg}\left(t-1\right)+{\sigma }_t}{t}$$

In this case, the mean and standard deviation of the moment calculated cumulatively at the current time may have the moment and the standard deviation at the current time reflected in the mean and the standard deviation of the moment cumulatively at the earlier time according to the following Eq. 10 and Eq. 11 were calculated. $$M_{avG}\left(t\right)=\frac{\left(t-1\right)\cdot M_{avG}\left(t-1\right)+M_t}{t}$$

$${\sigma }_{avG}\left(t\right)=\frac{\left(t-1\right)\cdot {\sigma }_{avG}\left(t-1\right)+{\sigma }_t}{t}$$

Here M _avg (t) and σ _avg (t) represent the mean and the standard deviation of the moment, which were calculated cumulatively at the current time, M _avg (t-1) and σ _avg (t-1) represent the mean and the Standard deviation of the moment, which were calculated cumulatively to the previous time, and M (t) and σ (t) represent the moment and the standard deviation of the current time.

For further reference, σ _avg (t) according to the following Eq. 12 can be calculated. $${\sigma }_{avG}\left(t\right)=\sqrt{\frac{{\displaystyle \sum M{\left(t\right)}^{\mathrm{2nd}}-t\cdot M_{avG}{\left(t\right)}^{\mathrm{2nd}}}}{t}}$$

As described above, when learning the statistical information of the moment is performed, a reference value with higher reliability can be generated when the statistical information of the moment is accumulated, and thus the reliability of the sheet condition determination can be improved.

Referring again to 3rd combines the reference value generation unit 60 the first reference value and the second reference value according to the weighting and generates an end reference value according to the following Eq. 13 ( S120 ) and represents the final reference value of the state determination unit 70 to disposal ( S130 ).

$$W_{max}=w_1\cdot W_{1-max}+w_2\cdot W_{2-max},{\text{ W}}_{min}=w_1\cdot W_{1-min}+w_2\cdot W_{2-min}$$

$$E_{max}=w_1\cdot E_{1-max}+w_2\cdot E_{2-max},{\text{ E}}_{min}=w_1\cdot E_{1-min}+w_2\cdot E_{2-min}$$

For example, if the reference value includes the caution reference value, the warning reference value, and the emergency reference value, the caution reference value (C _max , C _min ), the warning reference value (W _max , W _min ) and the emergency reference value (E _max , E _min ) can each be according to the following Eq. 13 to eq. 15 can be calculated. $${\mathrm{C.}}_{max}={\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">w</figure-callout>}}_1\cdot {\mathrm{C.}}_{1-max}+w_{\mathrm{2nd}}\cdot {\mathrm{C.}}_{\mathrm{2nd}-max},{\mathrm{C.}}_{min}={\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">w</figure-callout>}}_1\cdot {\mathrm{C.}}_{1-min}+w_{\mathrm{2nd}}\cdot {\mathrm{C.}}_{\mathrm{2nd}-min}$$

$$W_{max}={\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">w</figure-callout>}}_1\cdot W_{1-max}+w_{\mathrm{2nd}}\cdot W_{\mathrm{2nd}-max},{\text{W}}_{min}={\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">w</figure-callout>}}_1\cdot W_{1-min}+w_{\mathrm{2nd}}\cdot W_{\mathrm{2nd}-min}$$

$$E_{max}={\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">w</figure-callout>}}_1\cdot E_{1-max}+w_{\mathrm{2nd}}\cdot E_{\mathrm{2nd}-max},{\text{E}}_{min}={\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">w</figure-callout>}}_1\cdot E_{1-min}+w_{\mathrm{2nd}}\cdot E_{\mathrm{2nd}-min}$$

Here w ₁ and w _{2 represent} weights that are multiplied by the first reference value and the second reference value, respectively.

The caution reference value, the warning reference value, the emergency reference value and the measurement data of the moment generated by the series of processes are shown in 4th shown. It can be seen that because the leading edge 130 and the trailing edge 140 of the blade have points at which the torque is absorbed, an influence on the performance of the wind turbine or the fluctuation in the setting angle of the blade is not reflected.

The print page 110 and the suction side 120 of the blade, on the other hand, take an influence on the performance of the wind turbine and the pitch angle of the blade, and the reference value generation process in this case is described with reference to FIG 5 and 6 described.

5 12 is a flowchart showing a reference value generation process of a method for monitoring a wind turbine blade according to another embodiment of the present invention, and 6 and 7 are views to exemplarily show a reference value and torque measurement data by 5 were generated.

5 FIG. 12 shows a process of generating a reference value using the reference value generation unit 60 when a load measurement position the pressure side 110 and the suction side 120 of the sheet is, and the process is referenced to 5 described with focus differences from the above-mentioned embodiment.

As in 5 shown, the reference value generation unit calculates 60 first a first reference value based on the design information of the sheet ( S200 ). Because the step is the same as S100 the referring to 3rd described embodiment, a detailed description thereof is omitted.

Next, the reference value generation unit receives 60 Operating information of the wind turbine from the operating information input unit 50 ( S210 ). Here, the operating information includes information on the performance of the wind turbine and a setting angle of the blade.

Next, the reference value generation unit compares 60 the power of the wind turbine with a nominal power and determines whether the power of the wind turbine is the nominal power or less ( S220 ).

If the power of the wind turbine is the nominal power or less, since the torque is varied depending on the power of the wind turbine, the reference value generation unit reflects 60 a variation in the performance of the wind turbine in the statistical information of the moment ( S221 ) contrary.

On the other hand, if the power of the wind turbine is larger than the rated power, since the torque is varied depending on the pitch angle of the blade, the reference value generating unit reflects 60 the fluctuation in the angle of incidence of the blade in the statistical information of the moment ( S222 ) contrary.

Next, the reference value generation unit calculates 60 a second reference value based on the statistical information of the moment at which the fluctuation in the performance of the wind turbine or the fluctuation in the angle of incidence of the blade is reflected ( S230 ).

In particular, the reference value generation unit 60 calculate a length (a normal distance; L) of a normal section based on the mean and the standard deviation of the moment in which the fluctuation in the performance of the wind turbine or the fluctuation in the pitch angle of the blade is reflected, and the second reference value based on the mean of the moment , in which the variation in the performance of the wind turbine or the variation in the pitch angle of the blade is reflected, and the length L of the normal section.

$$W_{2-max}=\left(p\right)=M_{avg}\left(p\right)+s_3\cdot L\left(p\right),{\text{ W}}_{2-min}=\left(p\right)=M_{avg}\left(p\right)-s_4\cdot L\left(p\right)$$

$$E_{2-max}=\left(p\right)=M_{avg}\left(p\right)+s_5\cdot L\left(p\right),{\text{ E}}_{2-min}=\left(p\right)=M_{avg}\left(p\right)-s_6\cdot L\left(p\right)$$

For example, if the wind turbine power is nominal or less and the second reference value includes a second caution reference value, a second warning reference value, and a second emergency reference value, the second caution reference value (C _2-max , C _2-min ), the second warning reference value (W _2-max , W _2-min ) and the second emergency reference value (E _2-max , E _2-min ) each according to the following Eq. 16 to eq. 18 can be calculated. $${\mathrm{C.}}_{\mathrm{2nd}-max}=\left(p\right)=M_{avG}\left(p\right)+{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="DE112012004529B4\_0023.png"\; state="\{\{state\}\}">s</figure-callout>}}_1\cdot L\left(p\right),{\mathrm{C.}}_{\mathrm{2nd}-min}=\left(p\right)=M_{avG}\left(p\right)-s_{\mathrm{2nd}}\cdot L\left(p\right)$$

$$W_{\mathrm{2nd}-max}=\left(p\right)=M_{avG}\left(p\right)+s_{\mathrm{3rd}}\cdot L\left(p\right),{\text{W}}_{\mathrm{2nd}-min}=\left(p\right)=M_{avG}\left(p\right)-s_{\mathrm{4th}}\cdot L\left(p\right)$$

$$E_{\mathrm{2nd}-max}=\left(p\right)=M_{avG}\left(p\right)+s_5\cdot L\left(p\right),{\text{E}}_{\mathrm{2nd}-min}=\left(p\right)=M_{avG}\left(p\right)-s_6\cdot L\left(p\right)$$

Here, M _{avg represents} the mean of the moment, L represents the length of the normal section, and s ₁ to s ₆ represent statistical parameters. In addition, p refers to a parameter that represents the performance of the wind turbine.

If a parameter 9 , which represents the pitch angle of the blade, is replaced by the parameter P, if the power of the wind turbine is larger than the rated power, the second caution reference value, the second warning reference value and the second emergency reference value can be calculated by the same method.

Meanwhile, since a method for calculating the length L of the normal portion is similar to the embodiment, referring to FIG 3rd with the exception that the mean and standard deviation of the torque are represented as a function of p or θ, a detailed description thereof is omitted.

Because the reference value generation unit 60 that combines the first reference value and the second reference value according to the weighting to generate an end reference value and the end reference value to the state determination unit 70 ( S240 and S250 ), also essentially the same S120 and S130 of the embodiment with reference to FIG 3rd detailed description thereof is omitted.

Meanwhile, the caution reference value, the warning reference value, the emergency reference value, and the moment measurement data generated by the above-mentioned processes are shown in FIG 6 and 7 shown. 6 shows a reference value and moment measurement data related to the print page 110 , and 7 shows a reference value and moment measurement data related to the suction side 120 .

As described above, when the reference value serving as a reference of the sheet condition determination is generated according to the sheet design information and the statistical information of the moment, the reliability of the sheet condition determination in the steady state and in the non-steady state can be ensured.

8th FIG. 12 is a flowchart showing a blade state determination process of the wind turbine blade monitoring method according to the embodiment of the present invention.

As in 8th shown, receives the state determination unit 70 the moment from the moment conversion unit 40 ( S300 ) and the reference value from the reference value generation unit 60 ( S310 ).

Here, the reference value may include a caution reference value for determining whether the caution condition exists, a warning reference value for determining whether the warning condition exists, and an emergency reference value for determining whether the emergency condition exists.

Next, the state determination unit compares 70 the moment with the reference value to determine the condition of the sheet.

In particular, the state determination unit checks 70 whether the torque deviates from an upper limit or a lower limit of the caution reference value ( S320 ), and determines that the state of the sheet is the steady state when the moment corresponds to a value between the upper limit value and the lower limit value of the caution reference value ( S330 ).

On the other hand, if the torque deviates from the upper limit value or the lower limit value of the caution reference value, the state determination unit determines 70 whether the torque deviates from the upper limit or the lower limit of the warning reference value ( S340 ).

If the torque corresponds to a value between the upper limit value and the lower limit value of the warning reference value, the state determination unit determines 70 that the state of the sheet is the state of caution ( S350 ).

However, if the torque deviates from the upper limit or the lower limit of the warning reference value, the state determination unit determines 70 whether the moment deviates from the upper limit or the lower limit of the emergency reference value ( S360 ).

If the torque corresponds to a value between the upper limit value and the lower limit value of the emergency reference value, the state determination unit determines 70 that the condition of the sheet is the warning condition ( S370 ).

However, if the torque deviates from the upper limit or the lower limit of the emergency reference value, the state determination unit determines 70 that the state of the sheet is the state of emergency ( S380 ).

As described above, when the state of the sheet is determined as the caution state, the warning state or the emergency state, the state determination unit controls 70 the alarm unit 90 to issue an appropriate alert ( S390 ).

As described above, according to the apparatus and method for monitoring the wind turbine blade of the present invention, since the reference value serving as a reference of the blade condition determination is generated according to the blade design information and the statistical information of the moment, the reliability of the blade condition determination in the steady state can be and the non-stationary state can be ensured.

In addition, since the learning of the statistical information of the moment is performed, the reference value can be generated with higher reliability when the statistical information of the moment is accumulated, and the reliability of the sheet condition determination can be further improved. Accordingly, effective management and maintenance of the blade can be performed.

It will be apparent to those skilled in the art that various modifications can be made to the exemplary embodiments of the present invention described above without departing from the spirit or scope of the invention. Thus, the present invention is intended to cover all such modifications provided that they fall within the scope of the appended claims and their equivalents.

Claims (16)

A method of monitoring a wind turbine blade, comprising the following steps: Converting a load on the wind turbine blade of a wind turbine, which comprises at least the wind turbine blade, into a moment; Generating a reference value based on design information of the wind turbine blade and statistical information on the moment; and Comparing the torque to the reference value and determining a state of the wind turbine blade to enable efficient management and maintenance of the wind turbine blade, the generation of the reference value comprising: Calculating a first reference value based on design information of the wind turbine blade; Calculating a second reference value based on statistical information of the moment; and Combining the first reference value and the second reference value to generate the reference value; and wherein calculating the second reference value comprises: Compare a power of the wind turbine to its nominal power, the load being data measured on a pressure side or a suction side of the wind turbine blade. Procedure according to Claim 1 , in which the torque is converted based on the physical properties of a material and shape characteristics of the wind turbine blade. Procedure according to Claim 1 , in which the first reference value is calculated by reflecting a model parameter in a design load of the wind turbine blade. Procedure according to Claim 1 , wherein calculating the second reference value comprises: calculating a length of a normal section based on an average and a standard deviation of the torque; and calculating the second reference value based on the mean value of the moment and the length of the normal section. Procedure according to Claim 4 , in which, when calculating the length of the normal section, the mean and the standard deviation of the moment by reflecting a mean and a Standard deviation of the current time in an average and a standard deviation, which were calculated cumulatively to the earlier time, can be obtained. Procedure according to Claim 1 , where a fluctuation in the performance of the wind turbine is reflected in the statistical information of the moment when the performance of the wind turbine is the rated power or less, and the fluctuation in the setting angle of the wind turbine blade is reflected in the statistical information of the moment when the performance of the Wind turbine is larger than the nominal power. Procedure according to Claim 1 , wherein the reference value includes a caution reference value for determining a caution state of the wind turbine blade, a warning reference value for determining a warning condition, and an emergency reference value for determining an emergency condition. Procedure according to Claim 1 which further includes warning the state of the wind turbine blade when the state of the wind turbine blade corresponds to any one of the caution state, the warning state, and the emergency state. Device for monitoring a wind turbine blade of a wind turbine, comprising: a torque converter configured to convert the load on the wind turbine blade to a moment; a condition determination unit configured to compare the torque with a reference value and determine a condition of the wind turbine blade; and a reference value generation unit configured to generate the reference value based on design information of the wind turbine blade and statistical information of the moment, the reference value generation unit having a first reference value calculated based on the design information of the wind turbine blade and a second reference value based on the statistical Information of the moment was calculated, combined to generate the reference value; wherein the reference value generation unit is further configured to carry out a comparison of a power of the wind turbine with its nominal power, the load being data of a measurement on a pressure side or a suction side of the wind turbine blade. Device according to Claim 9 , in which the torque conversion unit converts the load into the torque based on physical properties of a material and shape features of the wind turbine blade. Device according to Claim 9 , in which the reference value generation unit reflects a model parameter in a design load of the wind turbine blade and calculates the first reference value. Device according to Claim 9 , in which the reference value generating unit calculates a length of a normal section based on an average value and a standard deviation of the torque and the second reference value based on the average value of the moment and the length of the normal section. Device according to Claim 9 , in which a fluctuation in the wind turbine power is reflected in the mean and the standard deviation of the torque when the power of the wind turbine is a nominal power or less, and the fluctuation in the setting angle of the wind turbine blade is reflected in the mean and the standard deviation of the torque when the Power of the wind turbine is greater than the nominal power. Device according to Claim 9 , in which the reference value comprises a caution reference value for determining a caution state of the wind turbine blade, a warning reference value for determining a warning state and an emergency reference value for determining an emergency state. Device according to Claim 14 wherein the state determination unit determines that the state of the wind turbine blade is the caution state when the moment deviates from the caution reference value, determines that the state of the wind turbine blade is the warning state when the moment deviates from the warning reference value and determines that the state of the Wind turbine blade is the emergency state when the moment deviates from the emergency reference value. Device according to Claim 14 further comprising an alarm unit configured to warn of the state of the wind turbine blade when the state of the wind turbine blade corresponds to any one of the caution state, the warning state, and the emergency state.

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